The present invention relates to a connection assembly for electrical cables, of the type for connection to connectors with cylindrical-pin terminals.
In particular, the connection assembly can be used preferably in the connection between the power supply cables of the electric motor of a compressor for electrical appliances and the cables for connection to the external mains.
An assembly for connecting electrical cables to connectors provided with cylindrical-pin terminals is known which is used typically in the connection between the power supply cables of the electric motor of a compressor for electrical appliances and the cables for connection to the external mains.
Said connection assembly comprises a connector made of plastic material, which is known in the field of reference also as “cluster” and forms internally mutually parallel guides for accommodating and stably locking respective electrical terminals.
These guides have, on a common wall of the connector, respective circular through holes, which can be used for the insertion of the cylindrical pins of the additional connector with which the connection assembly must associate (typically a connector with three cylindrical pins arranged like the corners of an equilateral triangle).
Each electrical terminal is constituted by a base, on which there is a region for crimping to electrical cables and a region for electrical contact.
At said electrical contact region there is a through opening in which it is possible to insert, in electrical contact with said terminal, a respective cylindrical pin of the additional connector with which the connection assembly must associate.
On mutually opposite sides of the base there are portions which are folded (so as to obtain a three-dimensional volume) and form means for locking the electrical terminal in the respective guide.
Said folded portions in fact protrude from the base outward in diverging directions and are flexible (flexing occurs transversely to the base).
The guides are narrower than the distance between the ends of the folded portions; therefore, during the insertion of each terminal in the corresponding guide, the folded portions flex toward the center of said terminal.
Wider regions are provided on the side walls of each guide and form abutments which are undercut with respect to the direction of insertion of the terminal in said guide.
Once the folded portions have reached said wider regions during insertion, they resume their initial (not flexed) shape, thus occupying the wider regions.
An abutment is provided on the bottom of each guide for the non-crimped end of the corresponding inserted electrical terminal.
The electrical terminal is thus locked between the recesses and the abutment.
With the terminal inserted in the corresponding guide, the circular through hole of the connector is superimposed on the through opening of the terminal for the insertion of the electrical connection pin.
This known type of connection assembly, however, has drawbacks linked both to the step for inserting the electrical terminal in the connector and to the step for crimping the electrical terminal to the corresponding cable.
The cantilevered parts of the folded portions designed to be deformed elastically by flexing are in fact limited in length (in the direction of flexing) due to issues of terminal bulk.
For this reason, the load for the insertion of the terminal in the connector is high (the folded portions flex scarcely because they are “short”).
This can lead to cases in which the terminal is not inserted perfectly in the connector, thus leading to an inaccurate superimposition of the circular through hole of the connector on the through opening of the terminal, making it consequently difficult or impossible to insert the cylindrical pins therein.
Moreover, for this same reason, the load for extraction of the terminal from the guide can be practically non-existent.
Another drawback occurs during the step for crimping the electrical cables to the electrical terminals.
Said crimping generally occurs by means of automated equipment, which comprises a small press under which the terminal and the cable are arranged.
The terminal is generally stored in a spool (in practice, the terminals are formed by a single tape which is pressed progressively).
The terminal is then brought to the press by unwinding the reel; the descent of the press cuts the terminal and deforms it so as to crimp the wire.
With terminals that can be used in this connection assembly, there are often problems during the feeding of the press; the unwinding of the reel is in fact problematic, owing to the portions that are folded laterally to the base of the terminal.
The folded portions of the contiguous terminals, by protruding toward the outside of each base, during the unwinding of the reel tend to interlock and become “entangled” with the contiguous terminals, requiring machine halting and operator intervention.